Changes In Vertebral Height Research Articles

P.148 Consult and kyphoplasty delay impacts on geriatric vertebral compression fracture outcomes

Background: Vertebral compression fractures (VCF) lead to both considerable morbidity and increased mortality. Kyphoplasty, a minimally invasive surgery, treats VCFs providing significant pain relief, preserving vertebral height, and reducing spinal deformity. Methods: A retrospective cohort study at Hamilton Health Sciences (HHS) was conducted on elderly patients (60 years or older) who underwent kyphoplasty at between 2012 and 2022. The patients had prior hospital admissions under non-spine-related specialties at HHS within two years before their surgery. Primary outcomes were the progression of vertebral height loss and focal kyphotic deformity. Results: The study included 119 patients (52.1% female, mean age 70.71 years). A significant increase in vertebral height loss was observed from diagnosis to pre-kyphoplasty (0.32% change, p < 0.0001) and from diagnosis to post-kyphoplasty (0.24% change, p = 0.015). However, there were no significant correlations between delay times and changes in vertebral height or focal kyphotic deformity. Conclusions: Delays in neurosurgical consultation and kyphoplasty did not significantly affect radiographic outcomes in elderly patients with VCF despite the progression of vertebral height loss. This suggests that while timely patient care is essential, delayed treatment may not adversely affect key radiographic metrics in elderly VCF patients.

Efficacy of Three Teriparatide Preparations and Romosozumab, Osteogenesis Promoters, in the Treatment of Fresh Vertebral Fractures: A Retrospective Observational Study.

In Japan, daily, twice weekly, and weekly formulations of teriparatide (TPD) and monthly formulations of romosozumab (ROMO) are available as osteogenesis promoters for the treatment of osteoporosis with a high risk for fracture. To compare the effects of three TPD preparations and ROMO on fracture healing and low back pain after a fresh vertebral fracture. This was a retrospective observational study. Patients presenting with fresh osteoporotic vertebral fractures were treated subcutaneously with TPD daily (DTPD), twice weekly (2/WTPD), weekly (WTPD), or with ROMO monthly. Bone union, vertebral height changes, and low back pain in the injured vertebra were compared after 6months of treatment. Bone union and pain improvement were more frequent among those who received daily and twice weekly administration of TPD compared with those who received WTPD and ROMO administration. A comparison for multiplicity between the groups using the Steel-Dwass test showed significant differences between the DTPD and ROMO groups (p = 0.0029) and WTPD and ROMO groups (p = 0.0490), suggesting superior bone fusion in the DTPD and WTPD groups. Similarly, significant differences were noted between the DTPD and ROMO groups (p = 0.0001), WTPD and ROMO groups (p = 0.0341), and 2/WTPD and ROMO groups (p = 0.0009), indicating a higher degree of pain improvement in the DTPD, WTPD, and 2/WTPD groups compared with that in the ROMO group. Daily, weekly, and twice-weekly administration of TPD may be superior to ROMO for promoting fresh vertebral fracture healing.

Use of a 3D-printed body surface percutaneous puncture guide plate in vertebroplasty for osteoporotic vertebral compression fractures.

Percutaneous vertebroplasty (PVP) has been used widely to treat osteoporotic vertebral compression fractures (OVCFs). However, it has many disadvantages, such as excessive radiation exposure, long operation times, and high cement leakage rates. This study was conducted to explore the clinical effects and safety of the use of a three-dimensional (3D)-printed body-surface guide plate to aid PVP for the treatment of OVCFs. This prospective cohort study was conducted with patients with OVCFs presenting between October 2020 and June 2021. Fifty patients underwent traditional PVP (group T) and 47 patients underwent PVP aided by 3D-printed body-surface guide plates (3D group). The following clinical and adverse events were compared between groups: the puncture positioning, puncture, fluoroscopy exposure and total operation times; changes in vertebral height and the Cobb angle after surgery relative to baseline; preoperative and postoperative visual analog scale and Oswestry disability index scores; and perioperative complications (bone cement leakage, neurological impairment, vertebral infection, and cardiopulmonary complications. The puncture, adjustment, fluoroscopy, and total operation times were shorter in the 3D group than in group T. Visual analog scale and Oswestry disability index scores improved significantly after surgery, with significant differences between groups (both p < 0.05). At the last follow-up examination, the vertebral midline height and Cobb angle did not differ between groups. The incidence of complications was significantly lower in the 3D group than in group T (p < 0.05). The use of 3D-printed body-surface guide plates can simplify and optimize PVP, shortening the operative time, improving the success rate, reducing surgical complications, and overall improving the safety of PVP.

A novel vertebroplasty technique using a larger-diameter needle for thoracolumbar osteoporotic vertebral compression fracture.

Percutaneous vertebroplasty (VP) and kyphoplasty (KP) are well-established minimally invasive surgical procedures for the treatment of osteoporotic vertebral compression fractures (OVCF). However, some drawbacks have been reported regarding these procedures, including height loss, cement leakage, and loss of the restored height after balloon deflation. We performed a novel VP technique to minimize these limitations of conventional procedures. This study aimed to compare radiological and clinical outcomes of our method using a larger-diameter needle versus conventional VP (using a smaller needle) for thoracolumbar OVCF.From April 2016 to May 2017, 107 consecutive patients diagnosed with thoracolumbar OVCF were enrolled. Patients were divided into two groups: group 1 underwent conventional VP, i.e., using a smaller diameter needle, and group 2 underwent VP through a modified method with a larger-diameter needle. For radiological evaluation, parameters related to anterior vertebral height (AVH) and segmental angle were assessed using plain standing radiographs, and patient-reported outcomes were evaluated using the visual analog scale. Cement injection amount and leakage pattern were also analyzed. Group 2 showed a larger anterior vertebral height change than group 1 immediately postoperatively and one year postoperatively. The 1-year postoperatively-AVH maintained better in group 2 than in group 1. Group 2 showed more significant improvement of segmental angle immediately postoperatively than group 1 (3.15° in group 1 vs 9.36° in group 2). IYPo-visual analog scale significantly improved in both groups, with greater improvement in group 2 (3.69 in group 1 vs 5.63 in group 2). A substantially larger amount of cement was injected, with a lower leakage rate in group 2 than in group 1.A novel VP technique using a larger-diameter needle showed superior radiological and clinical outcomes than conventional VP. Therefore, it can be considered a useful treatment option for OVCF.

Efficacy and safety of unilateral and bilateral percutaneous balloon kyphoplasty for AOspineA3/A4 osteoporotic thoracolumbar burst fractures.

To retrospectively evaluate the efficacy and safety of unilateral and bilateral percutaneous balloon kyphoplasty (PKP) in the treatment of osteoporotic thoracolumbar burst fractures.Retrospectively collected clinical data of 138 patients with osteoporotic thoracolumbar burst fractures who underwent unilateral (n = 70) and bilateral (n = 68) PKP in our hospital from March 2015 to December 2018. The general conditions, operation time, radiation exposure time, intraoperative blood loss, bone cement dosage, hospitalization expenses, and complications were collected from the two groups. Visual analog scale (VAS) values, Cobb's angle changes, average vertebral height changes, and Oswestry Dysfunction Index (ODI) values before treatment, 1 month, and 6 months after treatment were collected.There was no significant difference in gender (male: 28 vs 22; female 42 vs 46) and age (70.25 ± 7.10 vs 69.82 ± 8.20, P > .05) distribution between the two groups. The VAS score (7.38 ± 1.34 vs 2.52 ± 0.99, P < .05), ODI (77.24 ± 6.98 vs 23.11 ± 3.54, P < .05), vertebral mean height (16.71 ± 2.18 vs 17.05 ± 1.94, P < .05) and Cobb's angle (20.26 ± 3.21 vs 11.58 ± 3.20, P < .05) of the two groups were significantly improved after operation, but there was no significant difference between the two groups (P > .05). There was no significant difference in the rate of cement leakage (10.29% vs 11.42%, P > .05), incision swelling (30.88% vs 19.71%, P > .05) and incidence of adjacent vertebrae (4.41% vs 5.71%, P > .05) between the two groups. Compared with bilateral PKP group, operation time (50.88 ± 7.38 vs 62.18 ± 8.01), intraoperative blood loss (14.54 ± 3.16 vs 22.03 ± 5.92), radiation exposure time (23.74 ± 3.41 vs 15.22 ± 3.70), bone cement dosage (4.36 ± 0.81 vs 5.16 ± 0.77) and hospitalization costs (2.38 ± 0.08 vs 2.74 ± 0.07) were significantly lower in the unilateral PKP group (P < .05).Bilateral PKP and unilateral PKP have the same efficacy and safety in the treatment of osteoporotic thoracolumbar burst fractures. However, the unilateral PKP has the characteristics of short operation time, small trauma, low cost and short radiation exposure time, and has clinical application value.

Multi-Level Vertebroplasty for 6 or More Painful Osteoporotic Vertebral Body Compression Fractures Performed in the Same Procedural Setting: A Safety and Efficacy Report in Cancer Patients.

To assess safety and efficacy of multi-level vertebroplasty, when treating 6 or more levels in the same procedural setting for the management of osteoporotic vertebral compression fractures (oVCF) in cancer patients. Single institution retrospective review from 2015 to 2019 of patients treated for multi-level oVCF in a single session procedural setting by vertebroplasty of 6 or more levels. Procedure outcomes collected included procedural complications, pre- and 4week post-procedure pain score by numeric rating scale, opioid usage, and vertebral height changes. In total, 197 vertebral levels were treated in 24 procedures (mean 8.2 ± 1.8 levels). Mean procedure duration was 167 + / - 41min, and mean postoperative hospitalization duration was 2.1 + / - 1.9days. Four grade I or II complications occurred according to CIRSE classification. Two patients had a symptomatic pulmonary cement embolism; although there was no statistical difference between pre- and postoperative mean blood saturation (95.9 + / - 1.7% and 94.8 + / - 2.0%, respectively, p = 0.066). Pain score significantly improved after treatment (6.5 ± 1.3 vs 3.2 + / - 1.4, p < 0.0001) with a mean decrease of 3.3 (51%). Post-procedure daily opioid use also significantly improved (mean 35.8 + / - 36.8mg/24h vs 18.5 + / - 27.8mg/24h, p = 0.0089), with a mean decrease of 17.3mg/24h (48%). Refracture was found in 2 of 105 levels treated (1.9%), and no difference was found in thoraco-lumbar height and angulation. Five patients experienced new painful fractures at a non-treated level. Multi-level vertebroplasty for 6 or more levels is a safe and effective treatment for the management of multi-level oVCF in cancer patients.

Manual reduction combined with percutaneous vertebroplasty for the treatment of osteoporotic vertebral compression fractures with intravertebral clefts

To explore the therapeutic efficacy of manual reduction combined with percutaneous vertebroplasty in treating osteoporotic vertebral compression fractures(OVCFs) with intravertebral clefts. The clinical data of 94 patients with osteoporotic vertebral compression fractures with intravertebral clefts treated from January 2014 to January 2017 were retrospectively analyzed. The patients were divided into group A and group B according to different operative methods. In group A, 45 patients were treated with unilateral approach PVP, including 17 males and 28 females, aged (75.35±11.82) years old, with a bone density T-value of (-4.28±0.65) g/cm³; in group B, 49 patients treated with manual reduction combined with unilateral approach PVP, including 19 males and 30 females, aged (76.79±9.64) years old, with a bone density T-value of (-4.33±0.72) g/cm³. The operation time, bone cement injection volume and postoperative complications of two groups were recorded. The VAS and ODI scores of two groups were analyzed respectively at 1, 12, 18 months after operation. Vertebral height and kyphosis Cobb angle of two groups were compared immediately after surgery and 12, 18 months after operation. The distribution of bone cement in the vertebral body was observed and its distribution excellent rate was calculated. There was no significant difference in operation time between two groups. The amount of bone cement injection was(8.42±1.24) ml in group A and(9.19±1.09) ml in group B, and the difference between two groups was statistically significant(P<0.05). No spinal nerve root injury during operation and no complications including pulmonary embolism, bone cement toxicity and infection were found in two groups. There were 5 cases of bone cement leakage in group A and 4 cases in group B, which did not cause corresponding clinical symptoms and were not treated additionally. The distribution of bone cement in group A was excellent in 25 cases, good in 19 cases, poor in 1 case and in group B was excellent in 45 cases, good in 4 cases. The distribution excellent rate of bone cement was higher in group B than in group A (P<0.05). The VAS and ODI scores before operation and 1, 12, 18 months after operation were 8.29±0.74, 2.59±0.14, 3.75±0.38, 3.84±0.88 and 40.04±3.16, 9.24±2.82, 12.27±2.64, 15.83±2.58 in group A, 8.22±0.82, 2.54±0.19, 2.81±0.23, 2.82±0.45 and 39.98±2.05, 9.16±2.10, 9.46±2.41, 9.76±2.46 in group B. There was no significant difference in VAS and ODI scores at 1 month after operation between two groups (P>0.05), but group A was higher than group B at 12 and 18 months after operation (P<0.05). The vertebral height and Cobb angle before surgery, immediately after surgery, and 12, 18 months after surgery in group A were(59.17±1.42)%, (85.95±2.19)%, (75.27±3.45)%, (68.34±2.24)% and(23.83±3.37)°, (15.26±2.61)°, (17.63±2.16)°, (19.46±2.54)°, and in group B were(59.31±1.87)%, (89.19±2.53)%, (88.62±2.51)%, (88.59±2.62)% and(24.72±3.78)°, (14.91±2.28)°, (15.48±2.55)°, (15.86±2.81)°. Vertebral height Immediately after surgery was greater in group B than in group A and Cobb angle in group B was smaller than in group A (P<0.05). During follow-up, there was no significant change in vertebral height in group B, while vertebral body recollapse in group A(P<0.05). In the treatment of osteoporotic vertebral compression fractures with intravertebral clefts, the manual reduction combined with PVP is more effective than single PVP, which can effectively prevent vertebral body recollapse and improve the long-term efficacy of patients.

Comparison of 3D printed cervical spine with titanium mesh cage for fractures of lower cervical spine

Objective To compare the effectiveness of 3D cervical spine versus titanium mesh cage in the treatment of fractures of lower cervical vertebrae. Methods From May 2016 to March 2017, a total of 31 patients with cervical spine fracture were enrolled in this prospective randomized controlled trial at Department of Orthopaedics, Luohe Central Hospital. Of them, 16 cases were randomized to receive anterior cervical sub-total resection and decompression followed by internal fixation with implant of 3D printed cervical spine (3D group) and 18 to receive anterior cervical sub-total resection and decompression followed by internal fixation with implant of titanium mesh cage (TM group). The 2 groups were compared in terms of operation time, intraoperative bleeding, score and improvement rate of Japanese Orthopaedic Association (JOA), vertebral height change, cobb angle change and bone graft fusion. Results Eventually, included for this study were 15 cases in the 3D group and 16 in the TM group who had been completely followed up. Operations were well done for all the patients. The operation time for the 3D group (83.9±21.4 min) was significantly shorter than that for the TM group (116.2±27.8 min) (t=5.039, P 0.05). The vertebral heights and cobb angles at postoperative 3 months and at the final follow-up in the 3D group were significantly larger than those in the TM group (P 0.05). The incidence of prosthesis settlement in the 3D group (6.7%) was significantly lower than that in the TM group (43.75%) (P< 0.05). Conclusions Both surgical procedures can reconstruct cervical stability. Compared with titanium mesh cage, 3D printed cervical spine may lead to shorter operation time, better bone-material bonding interface, less prosthesis sinking and superiority in maintaining the cervical height and curvature. Key words: Cervical vertebrae; Fractures, bone; Dislocation; Titanium mesh cage; 3D printed microporous titanium vertebral body

Prognostic significance of increased bone marrow microcirculation in newly diagnosed multiple myeloma: results of a prospective DCE-MRI study.

Aim of this prospective study was to investigate prognostic significance of increased bone marrow microcirculation as detected by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for survival and local complications in patients with multiple myeloma (MM). We performed DCE-MRI of the lumbar spine in 131 patients with newly diagnosed MM and analysed data according to the Brix model to acquire amplitude A and exchange rate constant kep. In 61 patients a second MRI performed after therapy was evaluated to assess changes in vertebral height and identify vertebral fractures. Correlation analysis revealed significant positive association between beta2-microglobulin as well as immunoparesis with DCE-MRI parameters A and kep. Additionally, A was negatively correlated with haemoglobin levels and kep was positively correlated with LDH levels. Higher baseline kep values were associated with decreased vertebral height in a second MRI (P = 0.007) and A values were associated with new vertebral fractures in the lower lumbar spine (P = 0.03 for L4). Pre-existing lytic bone lesions or remission after therapy had no impact on the occurrence of vertebral fractures. Multivariate analysis revealed that amplitude A is an independent adverse risk factor for overall survival. DCE-MRI is a non-invasive tool with significance for systemic prognosis and vertebral complications. • Qualitative parameters from DCE-MRI are correlated with established factors of disease activity • Increased marrow microcirculation might be a risk factor for loss of vertebral height and fractures • Amplitude A is an independent predictor for shortened overall survival.

Percutaneous Vertebroplasty for Cephalad Vertebral Fractures After Instrumented Lumbar Fusion

Retrospective cohort study. To identify the effect of cement augmentation for cephalad vertebral fracture after instrumented lumbar fusion. Osteoporosis may contribute to cephalad vertebral fractures by an altered biomechanics in the adjacent segments due to the loss of motion at the fused segments. However, few studies on the treatment for cephalad fractures using bone cement augmentation after instrumented lumbar fusion have been published. Seventeen patients who had cephalad vertebral fractures after instrumented lumbar fusion underwent percutaneous vertebroplasty (PVP). All patients were divided into 2 groups according to the presence of intravertebral vacuum clefts (IVC) on plain radiographs and magnetic resonance imaging: group 1 consisted of 9 patients without an associated IVC and group 2 consisted of 8 patients with an IVC. The Oswestry Disability Index and the Visual Analogue Scale were recorded prospectively. The radiologic parameters of kyphotic deformity, vertebral height changes, and leakage of cement were studied. The Oswestry Disability Index and Visual Analogue Scale scores in group 1 decreased after PVP, but the mean score in group 2 was higher than in group 1 at the last follow-up. The mean kyphosis measured 15.7±7.4 degrees preoperatively and 15.6±7.1 degrees at the final follow-up in group 1, and 16.9±8.8 degrees preoperatively and 27.2±8.8 degrees at the final follow-up in group 2.The mean preoperative anterior and posterior vertebral height ratio measured 0.6±0.2 preoperatively and 0.6±0.2 at the final follow-up in group 1, and 0.6±0.2 preoperatively and 0.5±0.2 at the final follow-up in group 2.The mean preoperative middle and posterior vertebral height ratio measured 0.5±0.1 preoperatively and 0.6±0.1 at the final follow-up in group 1, and 0.5±0.1 preoperatively and 0.4±0.2 at the final follow-up in group 2. Four patients underwent revision surgery in group 2 and 1 in group 1. Although PVP treatment may be a useful method for cephalad vertebral fractures after instrumented lumbar fusion in elderly patients with persistent unremitting back pain, recollapse of the vertebral body can occur after a PVP for cephalad or adjacent vertebral fractures with an IVC.

CT fluoroscopy-guided vertebral augmentation with a radiofrequency-induced, high-viscosity bone cement (StabiliT®): technical results and polymethylmethacrylate leakages in 25 patients

To assess the technical results of CT fluoroscopy-guided, radiofrequency-induced vertebral augmentation (StabiliT®) in terms of vertebral height restoration and polymethylmethacrylate (PMMA) leakages, occurring in 25 individual patients with vertebral compression fractures and osteolysis. From 07/2010 to 08/2011, 25 patients (16 women, nine men; age 71 ± 14; range 41-89) with painful vertebral compression fractures due to osteoporosis (n = 19), metastases (n = 2) or multiple myeloma (n = 4) underwent vertebral augmentation with a radiofrequency-activated, high-viscosity polymethylmethacrylate (PMMA) bone cement (StabiliT® Vertebral Augmentation system; DFINE Europe GmbH, Mannheim) under local anesthesia. Thirty-four vertebrae (Th5-L5) were treated in 27 sessions under CT fluoroscopy guidance (128-row CT, Somatom Definition AS, Siemens, Erlangen) using a unilateral access and a cavity-creating osteotome prior to remote-controlled, hydraulically driven cement injection. 1/2/3 levels were treated in 21/5/1 session(s). Vertebral height change in the midsagittal plane (anterior, midvertebral, posterior endplate distance) and PMMA leaks were retrospectively evaluated using the postinterventional CT. All patients were successfully treated in the first session. Mean (MV ± SD) procedure time and amount of injected PMMA were 56 ± 14 min and 4.5 ± 1.4 ml, respectively. Mean anterior/midvertebral/posterior height gain was +7.1/+9.7/+0.4%. Small local vertebral leaks were observed in 18/34 vertebrae (53%) without any clinical sequelae. No major complications occurred. CT fluoroscopy-guided, RF-induced vertebral augmentation with a high-viscosity bone cement (StabiliT®) was safe and technically successful in all patients. Using a hydraulic cement injection technique, a moderate restoration of anterior and midvertebral height was seen while the system was not markedly superior to standard vertebroplasty regarding the frequency of minor asymptomatic PMMA leaks.

Long-term Follow-up of Percutaneous Vertebroplasty in Osteoporotic Compression Fracture: Minimum of 5 Years Follow-up

Study DesignThis was designed as a retrospective study.PurposeWe assessed the radiographic and clinical outcome of patients who underwent percutaneous vertebroplasty (PVP) in osteoporotic compression fractures with a minimum of 5 years follow-up.Overview of LiteraturePercutaneous vertebroplasty is effective surgical method for treating osteoporotic compression fracture.MethodsBetween January 2000 and August 2005, 159 patients were treated with PVP for osteoporotic compression fracture at our department; 43 patients died during follow-up, and 69 patients (121 vertebras) were available for follow-up for over 5 years. We analyzed the clinical and radiologic outcome including cement feature.ResultsThe mean follow-up period was 5.7 years. Clinical outcome by mean visual analogue scale (VAS) score revealed a decreased 4.9 points perioperatively. A decreased score was maintained over 5 years in 46% of patients. A new adjacent vertebral fracture was documented by 33 vertebral bodies in 22 patients. During the follow-up period, 43 patients (38%) in 112 patients died. Anterior body heig ht in the last follow-up was improved about 0.3 mm compared with the preprocedural value, but was not statistically significant. Also, the focal kyphotic angle was reduced from 12.3° at the preprocedural state to 11.7° at the postprocedural state, but was not statistically significant (p > 0.05).ConclusionsPVP for osteoporotic compression fracture is an efficient procedure for pain relief by long term follow-up. The cement injected vertebrae showed stable radiologic progression without significant changes in vertebral height or kyphotic angle.

Percutaneous Vertebroplasty for Vertebral Compression Fractures with Intravertebral Cleft: Cement Injection under Vacuum Aspiration

Purpose To evaluate the efficacy of cement injection under vacuum aspiration (CIVAS) of cleft contents in percutaneous vertebroplasty for osteoporotic vertebral compression fractures with an intravertebral cleft. Materials and Methods From April 2008 to October 2010, vertebroplasty for single-level osteoporotic vertebral compression fractures with clefts was performed in 34 patients (seven women, 27 men; mean age, 77 y) with CIVAS and in 41 patients (three women, 38 men; mean age, 77 y) by conventional injection (control group). In this retrospective study, the cement volume, cement ratio, visual analog scale (VAS) pain score, and incidences of leakage, new vertebral compression fracture, and nonhealing were compared between groups. Vertebral height changes in the CIVAS group were also evaluated. Results There were significant decreases in VAS scores in both groups ( P < .001). There were no significant differences in complications between groups (cement leakage, P = .70; new vertebral compression fracture, P = .17; nonhealing, P = .086). Vertebral height was significantly decreased by vacuum aspiration and increased by cement injection ( P < .001). The mean cement volume was significantly higher ( P = .0057) in the CIVAS group (4.87 mL) than in the control group (3.58 mL). Cement filling was achieved more sufficiently in the CIVAS group ( P = .014). Conclusions The CIVAS method is feasible and appears to improve cleft filling in the treatment of single-level vertebral compression fractures with a cleft, compared with conventional cement injection.

Is kyphoplasty better than vertebroplasty in restoring normal mechanical function to an injured spine?

Introduction Kyphoplasty is gaining in popularity as a treatment for painful osteoporotic vertebral body fracture. It has the potential to restore vertebral shape and reduce spinal deformity, but the actual clinical and mechanical benefits of kyphoplasty remain unclear. In a cadaveric study, we compare the ability of vertebroplasty and kyphoplasty to restore spine mechanical function, and vertebral body shape, following vertebral fracture. Methods Fifteen pairs of thoracolumbar “motion segments” (two vertebrae with the intervening disc and ligaments) were obtained from cadavers aged 42–96 years. All specimens were compressed to induce vertebral body fracture. Then one of each pair underwent vertebroplasty and the other kyphoplasty, using 7 ml of polymethylmethacrylate cement. Augmented specimens were compressed for 2 hours to allow consolidation. At each stage of the experiment, motion segment stiffness was measured in bending and compression, and the distribution of loading on the vertebrae was determined by pulling a miniature pressure transducer through the intervertebral disc. Disc pressure measurements were performed in flexed and extended postures with a compressive load of 1.0–1.5 kN. They revealed the intradiscal pressure (IDP) which acts on the central vertebral body, and they enabled compressive load-bearing by the neural arch ( F N) to be calculated. Changes in vertebral height and wedge angle were assessed from radiographs. The volume of leaked cement was determined by water displacement. Volumetric bone mineral density (BMD) of each vertebral body was calculated using DXA and water displacement. Results Vertebral fracture reduced motion segment compressive stiffness by 55%, and bending stiffness by 39%. IDP fell by 61–88%, depending on posture. F N increased from 15% to 36% in flexion and from 30% to 58% in extension ( P < 0.001). Fracture reduced vertebral height by an average 0.94 mm and increased vertebral wedging by 0.95° ( P < 0.001). Vertebroplasty and kyphoplasty were equally effective in partially restoring all aspects of mechanical function (including stiffness, IDP, and F N), but vertebral wedging was reduced only by kyphoplasty ( P < 0.05). Changes in mechanical function and vertebral wedging were largely maintained after consolidation, but height restoration was not. Cement leakage was similar for both treatments. Conclusions Vertebroplasty and kyphoplasty were equally effective at restoring mechanical function to an injured spine. Only kyphoplasty was able to reverse minor vertebral wedging.

Anterior versus combined anterior and posterior fixation/fusion in the treatment of distraction-flexion injury in the lower cervical spine

This study compared the results of combined anterior and posterior fixation/fusion with those of anterior fixation/fusion alone through a retrospective review of 50 patients with a distraction flexion injury of the cervical spine. Group A ( n = 28) had unilateral facet joint subluxation or dislocation (Allen stage I or II) and anterior fixation/fusion alone. Group B ( n = 10) had bilateral dislocation (Allen stage III) and anterior fixation/fusion alone. Group C ( n = 5) had unilateral subluxation or dislocation and combined anterior and posterior fixation/fusion. Group D ( n = 7) had bilateral dislocation or total dislocation (Allen stage III or IV) and combined anterior and posterior fixation/fusion. The following parameters were analyzed: the change in the vertebral height and Cobb’s angle, neurologic recovery, fusion time, fusion rate, surgery time, and the rate of complications. The mean fusion time was 3.75 ± 2.10, 6.00 ± 2.82, 3.60 ± 1.34, and 3.85 ± 2.26 months in groups A, B, C, and D, respectively. Group B had a significantly longer mean fusion time than groups A and D (Mann-Whitney U-test, P = 0,012, P = 0.014). There was a significant difference in the operation time between groups A and B and groups C and D. There were no significant differences in the changes in vertebral height and Cobb’s angle, fusion rate, and neurologic recovery. The complications encountered were three cases of distal screw loosening in group A ( n = 2) and B ( n = 1), and three cases of delayed union in group A ( n = 2) and B ( n = 1). There were no complications in groups C and D. In those with a bilateral dislocation, the fusion time was increased when only anterior fixation/fusion had been performed but the clinical results, such as neurologic recovery and complications, were similar in the four groups. Overall, anterior fixation/fusion alone in a bilateral dislocation is recommended as an alternative method.

Efficacy of Cyclic Intravenous Pamidronate Therapy for Children with Osteogenesis Imperfecta

Purpose: We report the results of cyclic intravenous pamidronate therapy for children with osteogenesis imperfecta. Materials and Methods: Fourteen patients with mean age 2.7 years were included in this study. Clinical evaluation included: fracture frequency, height gain, activity of daily living, and subjective changes. Bone mineral densitometry, simple radiographic findings, and the change in vertebral height were evaluated. Serum levels of calcium, osteocalcin and the urinary excretion of calcium and N-telopeptide of type I collagen (NTx) were monitored. Histologic study was performed on iliac crest apophysis biopsy samples. Results: Fracture frequency significantly decreased, from a pre-treatment 0.99 per year per patient to 0.28 per year per patient duringtreatment. Height gain was not affected. Five patients reported subjective improvement. Bone mineral density increased in both lumbar spine and the femur neck. Urinary excretion of NTx and calcium were significantly reduced during each treatment cycle, but were restored at the following cycle. Eleven patients had transient asymptomatic hypocalcemia. A transient febrile reaction was observed in 8 patients during the first cycle, and 4 patients showed a mild increase in the serum transaminase level. Conclusion: Cyclic intravenous pamidronate treatment is safe and effective for children with osteogenesis imperfecta.

4:25 Repair of osteoporotic vertebral compression fracture by transpedicular injection of bioactive calcium phosphate cement into the vertebral body

Purpose of study: Percutaneous vertebroplasty (VP) and kyphoplasty (KP) have been successfully used for the treatment of osteoporotic vertebral compression fractures (VCFs). Although polymethylmethacrylate has been exclusively used and seems to be useful in the clinical series of VP and KP, it seems not to be an optimal material because of several potential disadvantages. We have developed transpedicular injection of bioactive calcium phosphate cement (CPC) into the vertebral body for repair of osteoporotic VCFs and pseudarthrosis without neurological involvements. We report the clinical experience of this new treatment for painful VCFs.Methods used: We prospectively followed up 38 patients with 41 vertebrae treated with this procedure, including 19 fresh fractures, 3 delayed unions and 19 vertebral pseudarthroses. The average age of the patients was 71 years old, and the follow-up period was 15 months on average (3 to 70 months). Radiological examinations are performed for all patients to evaluate progression of collapse, radiolucent line around the CPC, vertebral height change at flexion-extension lateral views. Wedging rate is defined as a percentage of the anterior vertebral height to the posterior one in a lateral view and is evaluated in all patients before and after the surgery and at final follow up. Preoperative and postoperative pain was assessed using a 10-point scale.of findings: All patients had significant pain relief. The average 10-point pain scale was 8.4 preoperatively and improved to 0.9 postoperatively. Radiological examinations 3 months after treatment to the final follow-up demonstrated no progression of vertebral collapse, no radiolucent zone around the CPC and also no detectable changes of the vertebral height at flexion-extension views in all cases of fresh VCFs and delayed union, and in 18 of 19 vertebrae of pseudarthrosis. In case of fresh fracture, the wedging rate is 66% before treatment and 84% immediately after treatment. Seventy-nine percent were maintained up to the final follow-up at 30 months after surgery. No loss of correction was observed after 1 month. As for pseudarthrosis, the rate is 28% preoperatively, 61% postoperatively and 49% at final follow-up of 13 months after surgery. The correction loss, which is not associated with back pain, occurred within 3 months postoperatively, but afterward never. Two patients had asymptomatic complications. One was minor intracanal leak, and the other was extravertebral migration of fragmented CPC 1 month after surgery, which suggested the failure of repair. There were no other significant complications in this series.Relationship between findings and existing knowledge: The CPC we used is injectable, nonexothermic, self-setting, is bioactive cement with osteoconductivity and sets by hydration to change composition into carbonated hydroxyapatite. Direct bonding of CPC to the surrounding bone and new bone formation around the CPC were described in the literature. Its compressive strength increases over time and reaches the maximum in about 7 days after injection. The maximum value is over 80 MPa, which is strong enough to reinforce the collapsed vertebrae. The clinical and radiological outcomes in this study suggest that the fractures have been successfully repaired by the injection of the CPC, except one case of pseudarthrosis.Overall significance of findings: The transpedicular injection of CPC is safe and effective for pain relief and stabilization of the fractured vertebral body and might have potential advantages over the VP and KP because of the excellent biocompatibility of the CPC.Disclosures: Device or drug: calcium phosphate cement: Biopex, Mitsubishi Materials Corporation, Tokyo, Japan. Status: not approved.Conflict of interest: No conflicts.